As almost anyone who has driven an automobile will appreciate, it is imperative to provide as much road illumination at night as is possible without distracting oncoming drivers. Accordingly, it is almost essential that both of the low beams be in operation since the constant use of high beams is generally totally unacceptable in areas of high traffic, where, with the high beams, there is a tendency to blind drivers coming in the opposing direction.
Obviously the driver of an automobile will be immediately aware of a situation in which both of the low beams have failed. However, in instances where only one of the low beams fails, it is often the case that although the amount of illumination from the front of the car is decreased, it is not substantial enough to alert the driver of the vehicle. Again it is to be appreciated that driving with only one low beam is often very disconcerting to oncoming traffic.